Transmission line clamp



Jan. 12, 1932. w. P. LARK TRANSMISSION LINE CLAMP Filed March 28, 1929INVENTOR. ,PLQf/fl,

ATTORNEZ Patented Jan. 12,1932

TRANSMISSION LmncLAnrP Application filed Marcl128, 1929.SeriaiNoJ35Qg789i, a

The present invention consists of a trans-,

mission line clamp, an objector which is toprovide a'cable suspensionmember which is adapted to hang the cable without theuse of snatchblocks or like hoisting means heretofore employed for engagingthe cablewith the conventional insulator clamp.

Another object of the invention is toprovide a clamp in which the cablemay be hoisted and then tensioned, after which the cable. is positivelysecured from *moVement or displacement. V

A further object of ;.the invention is to providea transmission lineclamp which may be utilized for hoisting the clamp to the insulatorgroup and the cable stretched there-, through to the'desired degree oftension, pursuant to whichthe cable may beclamped into a fixed positionin a facile and expeditious mannen- J V y A 'stillfurther object of theinvention ;is to provide a clamp through which the cable may bestretched and afterwards secured, the clamp being equippedwith highlyconduc tive metal to increase'conductivity at the same time reducingfrictional resistance during'the cable-tensioning operation to aminimum.

Other objects ofthe invention will heapparent from the followingdescriptionof the present preferred forinof the invention,

aken in connection with theaccompanying drawings, wherein Fig. 1 is aside elevational view of a transi mission line clamp constructed inaccordance with the present invention, illustrating the application ofthe same; I

V Fig. 2 is a longitudinal sectional view of the line clamp, showing thecable linein dotted lines, andrillustrating the, clamp applied to theinsulator arm, ,the latten beingg shown fragmentarily Fig. 3 is averticalsectional view, taken on the line 3-3 of Fig.2, looking therection of the arrow;..

"Fi .4 is a'vertical sectional. view, ftaken on theline 4-4101 Fig. 2,lookinginthe di rection oi:"the"arro.w;

,tion'7 of the cross-arm of a line wire and isequipped on thefreeterminal'with eye '8. i of discal insulators 9 fromith'eilowermostof 60,

.versely across the frame and j with a; wear 1 the V roller.

Fig.5 isa vertical sectional view,taken on the line 5 ri igi 2,1aaaghermal-Lon 1 of the arrow'; and l Fig. 6 is a plan View of the clampplate, f 7

In the drawings, in orderto illustrate the I .appl1cat1on of the presentinvention,

is shown, whichis, of; conventional. design, an

The, eye pendently carries a; group which a'narm lO pen'ds; g The clampconstructedin accordance with thepresentinventionis'generally'designatedl an mbodi s i c y p n a d:

a clamping plate-l2. The frameof the c amp; consists ofparallel sideplates; 13, which are integrally connected through the medium of webs14,- the inner facesofthe latterbeing concaved and preferably plated orotherwise equipped with a highlylconductive film15, l .madeof aluminumcomposition or like mate- 1 rial. Transmissionline receiving saddlesare"thereby provided. The webs 14 extend trans- 16 mounted therebetween.Rollers, 17.21MB

mountedbetweenthe plates 13 atthe ends of the frame, beyond-the outerterminals of the,

.webs -14. .Tlie; outer terminals of the frame extend downwardlybeyond-the" rollers 17 to -provide iurshaped guard members 18, for f apurpose-more fully-hereinafter set forth,

Each of the rollerslfi and 17 is preferably composed'ofamaterialofhighly electrical conductivity, the borefof which is providedbeing keyed orotherwise fixedly :secured to Each roller is. adapted/to,be ro-' I tata'blymounted ona'shaftor axle 20, which is made of suitablewear-resisting metal, such Ta's malleable steel, the shafts orlaxlesbeing 0. i fixedlysecured-tothe traine. When the roll- Y .e s m m eflinihezirame w b ct j especially. upon regie re 'oe to Fig. 2 fofthefdrawings, that the vertlces of the cable -im- ,4 pingingportions'thereof arein a plane above h Plane f f heii we p r ions a;

the fra e, ,Consequently,when amnesia; 1

line cable,-,}suclras indicat ed at21,.1is drawnthro'ugh the clamp, thecable. willjpass 1 00 j freel y over merciless clear the I p ate 1 havearoller Q I take-up sleevef 19, the flatter 85 p films or saddles 15. Theprovision of rollers permits the cable to be drawn through the clampwith a minimum resistance. After the cable has been drawn to the desireddegree of tension, it may be clamped into fixed threaded as indicated:at 24, and extends through the web 1 1 and is adapted for the receptionof a nut 25. The nut 25 is threaded on the shank of its bolt until it isengaged 'with the under face of one of the webs 1 1 or with a washer 26,which is interposed between thenut and the web to thereby draw the billof the hook downwardly and correspondingly urgethe clamp plate 12inwardly so as to flex the cable'21 snugly in engagement with the platedfilms 15 of the webs 14. It

will be noted that the inner face of'the'plate 12 is plated or providedwith a covering 27 of highly conductive metal, such as aluminumcomposition. 1 When the plate 12 is secured serves as a cushion for thecable 21.

in position, as shown in the drawings, it will be'noted that said cableis almost completely encased in the clamp between the bottom and sidesof the frame and theclamp plate 12. l/Vhen so clamped, the covering orplating 27 Consequently, po'sssibility of cutting the strands of thecable or of corrosion of the latter, by contact with the rough steelclamp commonly used, is eliminated. The clamp plate is bowed midway itsends, as indicated at 28, to

- conform to the contour of the central'roller quently,

16, above'which it is positioned. Consewhenthe plate 12 is urgedinwardlyagainst ,thecable 21 the latter is fixed from movement against theperiphery of'the roller 16. r

The side plates 13 of the frame are provided with intermediate ears 29,which, as shown to advantagein Fig. 3, are, arranged in parallelrelation and are provided with openings therein which correspond withopenings formed in the insulator armlO and are adapted for the receptionof a bolt or pin 30 which is'deta'chably engaged through said ears 29and arm 10. v

- In engaging transmissionline cables with group insulators on th'ecross-arms of line towers, 1t 1s customary to first engagethe cable witha snatch block which is then hoisted into engagement with the eye 8 ofthe cross-arm, following which the cable is tensioned to thefdesireddegree'and then transferred to a clamp, consisting, of plate U- T hebill of each hook is adapted present invention, with shaped incross-section, which is pendently supported by the insulator group. Thisprocedure is both costly and laborious. With the present invention theuse of snatch blocks is eliminated, since the clamp is directly engagedwith the insulator group on the ground and the cable mounted in theclamp, after which the insulator group and clamp are hoisted intoengagement with the eye 8 of the cross-arm, while the cable is slack.This hoisting operation is a simple one and may be performed by the useof an ordinary pulley block and a small expenditure of man-power. Afterthe group of insulators and clamp constructed in accordance with thepresent invention is secured to the cross-arm, the cable is tensioned ina manner well known in the art, following which the cable is positivelysecured from displacement, in a manner already described. It isdesirable to main the clamp, material of high electrical conductivitywhich is usuallyra soft metal and consequently issubject to rapid wearby the frictional resistance set up when a cable is pulled therethrough.By the provision of rollers, as herein set out, the cable is drawnthrough the clamp with an'almost completeabsence of frictionalresistance, since the cable, by reason of the peculiar positioning ofthe rollers, comes in contact with no part of the clamp body." However,by reason of the structure above described, when the cable isclampedfrom movement in the present invention, it is almostcompletelyhoused by a casingofhigh electrical conductivity,with obviousdesirable advantages. Complete assemblage of the clamp and insulatorgroup on the ground may be effected by use of the p 7 the exceptionofthe clamp plate 12, which may be inserted in the clamp body above thecable after the latter has been tensioned. It will be noted that theplates 13 are recessed, as indicated at 31, for the reception of theclamping bolts 22, the bills of the latter being'adapted to rest insemi-circular recesses theupper margins of the plates 13, during thetensioning operation of the cable. As soon as the cable has beentensioned and the plate 12 positioned on top of the cable, the clampingbolts 22are rotatedso as to engage the bills of the bolts in the.recesses 23 of the clamp plates, as heretofore described. The provisionof the guards 18 prevent the cable from flexing downwardly, so as toalso prevent drag-againsttherollers 17 during the tensioning operationof the cable. This further eliminates the possibility ofany unduefriction .or wear. on the rollers. i

' Although the present invention is shown as especially adapted" for usewith soft metal Jcable, it is nevertheless to be understood that the:clamp is" equally I applicable for use with hard metal cable andcorrespondingly, the

re le te am beer i fl e la y be 32 which areformedin made of hard metal'throughout. The manner of associating the clamp with the insulator groupand the theory of operation remains the same.

While I- have herein described the present preferred form of theinvention, it is nevertheless to be understood that various changes maybe made in the invention, especially in V the details of construction,proportion and arrangement of parts, within the scope of the claimshereto appended. i

What is claimed is V 1 1. In a cable clamp for the insulators oftransmission line towers, includinga clamp embodying a plurality ofuniplanar movable cable engaging parts, and means to clam the cableagainst said parts.

2. In a cable clamp structure, m'obile means to permit: frictionlessfeeding of the cable therethrough, cable into fixed engagement with saidmeans.

3. In a cable clamp for the insulator group a clamp body of atransmission l ne tower, I equipped with rollers, cable seats formed inthe body between said rollers, and means detachably mounted in the bodyto urge the cable into engagement with said rollers and seats.

with a plating of highly conductive metal, a series of'rollers mountedin the clamp between said seats,

material said plate urging the cable into eugagement with the seats androllers. v T

5. A cable clamp including a. clamp body equipped with a meansengageable through said clamp body and with the clamp plate for urgingthe latter in the direction of the seats and rollers.

WILLIAM P. LARK.

and means to urge the 4. A cable clamp including a clamp emf bodyingcable seats, each of which is equipped.

and a clamping plate 7 equipped withaplating ofhighly conductive seriesof-rollers and interposed cable seats, a clamp plate mounted in theclamp body over said seats and rollers, and l

